Air compressor



G. J. SPOHRER AIR COMPRESSOR April 16', 1935.

Filed Aug. 30, 1953 INVENTOR ITNESSES Gregowb J'Spohr'er Y a W ATTORNEYS Patented Apr. 16, 1935 UNITED STATES The present invention relates to air compressors, andit has for its object to provide such a device of simple and effective construction and one which shallbe practically noiseless inoperation. 1

A further object is toprovide for effective lubrication without liability of contaminating the air delivered to the tank.

A further object is to construct and assemble the parts so as to practically eliminate and absorb vibrations and to avoid metallic contacts;

between adjacent parts with the resultant chattering. V Further objects will appear in connection wit the following specification. To the above endsthe present invention consists of an air compressor comprising a motor and pump constructed and operating and provided with means to prevent vibrations or the direct loose contact of movable metal parts with each other liable to cause chattering, and it further consists of the devices and'combinations of devices which will be hereinafter described and claimed. u v

The apparatus is shown in the drawing in which Figure 1 shows partly in elevation and partly in cross section the apparatus and the enclosing accompanying and protecting dome mounted on the upper end- 'of the storage tank, the upper'portion only of which is shown; v V

Figure 2 is an enlarged cross sectional detail taken on the same diametrical line as the sectional parts shown in Figure 1, cutting also the piston which is shown in elevation in Figure 1,"

Figure 3 is a sectional view taken on the line 33 in Figure 1 looking inthe direction of the arrows in that figure. I

Similar reference characters will, be employed throughout the specification and drawing to designate corresponding parts. i

In the drawing I indicates the storage tank for the compressedair, made of metal in any usual manner and having a flat top 2 with a rounded shoulder 3, about its upper edge. metallic dome 4 made of metal of suitable thickness and strength and preferably without a seam, as by a spinning or other process, has its lower open end of practically the same diameter as that of the storage tank I, and the edge 5 is shaped to closely fit and contact with the rounded shoulder 3 of the storage tank I as shown in Figure l of the drawing. As the dome 4 is made of relatively thin metal, and as the vibration of the parts contained within the dome, if transmitted thereto, might produce an objectionable noise, I have provided a dampering device 6, consisting of. a mass of some inert metal such as a lead which when melted is deposited upon the -inner surface of the upper end of the dome,

the motor securely in position while permitting a preferably in a circular form, which willefiectively in' combination with other instrumentalities to be described, prevent not only any bodily movement of the dome but also all vibratory ac-' tion of the wall of the dome. Inorder to hold the dome firmly in position with the open end 5 in close contact with the'shoulder 30f the tank 3 I, I have provided a bail l which at its lower f end is firmly secured to the top of the tank I by bolts 8 as shown in dotted lines in Figure 1,

it being understood that the bail is provided withtwo downwardly extending members, which straddle the motor, only one 'of which is' shown in Figure 1, but both of which will be firmly secured to the top of thetank I, as shown and described. The curved upper portion of the bail l is provided with a threaded opening 9 to receive the threaded end of a bolt 10 which passes through a central opening formed in the top of thedome 4 and through the dampering reenforcement'G andthrough a fibrous washer II and a metallic washer I2 disposed beneath the head I3 of the bolt liL-qThis arrangement is such'that the domewill be firmly secured in position so that the curved edge '5 of its lower openend will be tightly held against the shoulder'3 of the tank l'so that there will be no pos-' sibility of any movement of the dome 4 and no vibration of the same and it will be tightly held without any metallic contact between the head I3 0 projections I8 surrounding the bolts l5. The base plate l9 of the motor 1 4 is provided with openings 29 into which are fitted and'held rubber or other elastic bushings 2| through which the bolts I5 pass. At their upp'erends the bolts [5 are provide'd with flanged nuts 22 which may be adjusted in relation to the top 2 of the tank I so as to hold slightyielding-motion thereof on its support and to some extent limiting the rise and fall of the motor as permitted by the yielding support. While only two of the spring supports for the motor are shown it will be understood there will be four'of such supports, two on opposite sides of the longitudinal central line of the axis of the motor; Q e

The motor carries a crank case 23 aflixed thereto in any suitable manner as by means of the bolts 24, within which is positioned a crank 25 held 1 g by a screw 26 to the shaft 21 of the motor (see I dotted lines, Figure 1). The crank 25 carries a? crank shaft 28 to which is connected the lower case.

end of a piston rod 29, by means of an anti-friction bearing including an oil groove 30 formed in the surface of the crank shaft 28. To the outer end of the crank shaft 28 is fixedly secured a crank 3I which is provided with an oil channel 32 which leads to the bearing of the crank shaft 28. The outer end of the crank 3I is provided with a grooved stud in axial alignment with the shaft 28 engaging and supporting a loose metallic ring 34 of sufiicient circumference to extend below the level of oil in an oil pocket 35 which receives oil from an oil reservoir 36 formed in the lowerportion of the crank case and which may be covered by a covering plate 31 resting on a supporting partition 38 provided with an opening 39 through which the oil may flow from the reservoir 35 to the oil pocket 35. By means of this oiling device comprising the stud 33 ring 34 and the crank 3I oil is delivered in proper amounts through the channel 32 to the crank shaft 28. The crank case at its outer end is provided with an opening 40 normally closed by a plate 4| held in position by screws 42, by means of which access will be afforded to the interior of the crank case. An air inlet may be provided if required, as indicated in dotted lines in Figure 1. 7

The crank case is rigidly connected to the frame of the motor I4 and is supported thereby; but in order to insure that the weight of the motor and pump shall be carried in such manner as to absorb vibrations and to prevent as nearly as possible any chattering which might be caused by vibrations, a coil spring 43 is placed beneath the crank casing with its lower end seated about a boss 44 carried by the top of the tank I and at its upper end a boss 45 on the under side of the crank case 23. 1

Apiston 46 is pivotally connected to the upper, end of the piston rod 29 as by means of a coupling pin 41 which is carried by a bearing 48 at the upper end of the piston rod 29. The'chamber 49 of piston 46 will extend to the upper end which will be provided with ports 58 above whichis seated a valve plate 5| loosely mounted on a screw 52 which carries a convex washer 53 permitting a slight up and down movement of the valve plate 5|, the arrangement constituting the intake valve permitting air to flow into the cylinder above the piston. The piston cylinder 460 is mounted in a threaded bearing 54 at the upper part of the crank At is upper end there is connected thereto by a threaded joint 55 a cap 56 provided with ports 51 and holds in position on the upper end of the piston cylinder 48!! a valve seat 58 provided with ports 59. mounted upon and held in position above the valve seat so as to close and open the ports 59 by means of a circular boss 6!, a washer 62 and a screw 63. Between the valve plate 60 and the inner surface of the cap 58 is arranged a coil spring 64 the upper end of which is seated in a recess 65 and the lower end of which bears against the valve plate 50; The cap 56 forms a part of a casting which comprises also a base plate 66 and a wall 61 having an opening 68 at the top which receives a threaded plug 59. Between the cap 56 and the wall 61 is formed a chamber which is filled with a suitable closely packed fibrous material III in the form of a coiled cord or rope as shown in Figure 1. Be-

tween the material III and the outer surface of the cap 56 and covering the ports 51, is a protective A valve plate or disk BI) is loosely while the material 10 serves to separate or remove any oil which may have become mixed with the air from the latter, and thus prevents oil from being forced out of said chamber.

It will be understood of course that the upward movement of the piston forces air through the chamber and effects the automatic lifting of the valve plate 60 to open the ports 59, and the downward movement of the piston will permit the valve plate 60 to drop to close the ports 59, and will at the same time cause the opening of the valve 5| to permit air to flow in above the piston, to be again forced out on its upward movement. The air passes through a pipe 12 and through an automatic check valve 13 and through a pipe 74 and a section of rubber or other suitable flexible tubing 15 into the tank I through a coupling 16 which connects the lower end of the tube 15 to the top of the tank I. The moreair that is forced by the pump into the t nk I the more it will be compressed, as will be early understood.

The lower end of the pipe 14 is connected by a T-coupling TI to an automatic pressure control 18 which by means of a bracket 19 is mounted on the motor I4. Electric current is conducted from any suitable source of supply by means, of an electric cable 80, which at its upper end leads into a switch (not shown), by means of which the motor may be driven and which is automatically turned on or ofi as required by the pressure in the tank II, by the pressure control 18. The electric cable passes through an insulated bearing 8I supported by a bracket 82 mounted on the top of the tank I and passes out through an opening in the wall of the dome 4 protected by a relatively soft rubber gasket 83 having a central opening through which the insulated bearing 8I' passes. Thus the parts are doubly insulated at the point where the electric cable 80 enters the dome,-and the insulated opening is of such a character that there will be no chattering between the parts at that point.

In operation, assuming that electric current is passing through, the cable 80 the motor will be driven, imparting reciprocations to the piston 46 which on its down stroke takes in air from the crank case which enters the latter through the motor casing and on its up stroke forces the airout through the pipe 12 and its connections,

into the tank I. Should the pressure in the tank I exceed a point of safety the governor 18 will automatically operate the switch to shut oiif the motor and as the pressure declines in the tank I the switch will automatically start the motor.

By means of the arrangement shown, effective lubrication of the movable parts is assured and there will be practically-no noise whatsoever in the operation of the pump or motor, nor will there be any vibrating contacts of metal which will produce a chattering noise. Of course the tank I will be provided with the usual valve controlled outlet 84.

It will be understood of course that the flexible tubing I5 will be of such length as to be somewhat slack as indicated in Figure 1, thus permitting a slight vertical movement of the motor and pump while in operation, and as before explained, it being preferably non-metallic, even though it may rest upon the motor there will be no sound produced as a result of the vibrations permit-ted by the yielding support of the motor and pump. This is also true of the electric cable 80 in which there is sufiicient slack provided, and as usual in such cables, the wires will be covered by a nonmetallic insulation.

not be displaced during the rotation of the crank.

25, so that the ring 34, whilefree to turn with the stud 33 will not be displaced laterally or vertically. A suitable stop 85 projecting from the inner face of the cap 4| is positioned over the ring 34 thus insuring that it will at all times remain in the groove 33 of the crank 3| although free to turn about the crank 3| as the same revolves, thus delivering oil from the pocket 35 which will flow through the oil channel 32 and thus be delivered to the grooves in the crank shaft 28.

It is to be noted that the soft rubber gasket 83 or the centrally disposed connecting portion thereof is smaller in diameter than the opening in the wall of the dome 4 and thus may be adjusted slightly, permitting the proper positioning of the cylindrical extension of the insulated bearing 8! supported by the bracket 82. It is to be further noted that the oppositely disposed registering bosses on the top of the tank I and on the combined motor and pump serve to properly position the spiral springs which support the 1 combined motor and pump and insure that they will remain in position during the operation of the apparatus.

As there is no displacement of the grooved stud 33 upon which the oiling ring 34 is mounted, in operation the ring will be slowly turned, picking up a relatively small part of the oil in the ,oil pocket 35. There will be no splashing of the oil by the operation of the oiling ring. This insures that while a sufficient amount of oil will at all times be delivered to the crank shaft there will be no excess of oil, and should any oil reach the piston and be expelled thereby into the chamber at the top of the pump it will be taken up by the tightly coiled fibrous, preferably fireproof cord packing tightly packed in the chamber and the air expelled by the pump and delivered to the tank will be absolutely free from oil or other impurities.

I claim:

1. In combination, a tank, a motor, an air pump, yielding supports therefor connecting the motor and pump to the top of the tank, a dome enclosing the same, means to prevent vibrations of the dome, and means detachably connected to the top of the dome to clamp and hold the dome in place on the tank.

2. In combination, a motor, an air pump, yielding supports for the motor and pump, a storage tank, a dome having its open lower end fitted to the top of the tank and enclosing the working parts, means to clamp and hold the dome to the top of the tank, an air outlet connected with said pump, and a pipe leading from the outlet to the tank, said pipe including a flexible section to accommodate the vibrations of the motor and pump on the yielding supports.

3. In combination, a tank, a motor and pump yieldingly supported on the top of the tank, a dome of substantially the same diameter as the tank, a TOLllldBd shoulder about the upper edge of the tank and the edge of the lower open end of the dome formed to fit said rounded shoulder, a yoke within the dome, straddling the motor and bolted at its lower ends to the top of the tank, a threaded bolt passing through the center of the top of the dome and engaging a threaded opening in the top of the yoke, a non-metallic washer located beneath the head of the bolt and in contact with the outer surface of the dome, and a casting of inert metal formed upon the inner surface of the top of the dome and surrounding the bolt which engages the yoke.

4. In combination, a motor and an air pump, the air pump being afiixed to and projecting from the motor, bolts passing through apertures in the base of the motor and surrounded by coil springs for yieldingly supporting the motor, non-metallic bushings surrounding the bolts, said bushings being carried by the base of the motor, and a coil spring located beneath the crank case.

5. In combination, a motor and pump, a yielding support therefor, a storage tank, a dome mounted on the tank, enclosing the motor and pump, means for conducting air from the pump to the tank, said means including a flexible tube, means to fixedly secure the dome to the upper end of the tank, an opening leading from said dome, a non-metallic bushing surrounding the opening, and a non-metallic bearing for supporting an electric cable as it passes intothe dome.

6. In combination, a storage tank, a motor and a pump, said pump comprising a cylinder and a piston in the cylinder connected With and operated by the motor, a chamber mounted on the top of the cylinder in axial alinement therewith enclosing the valves of the pump, said chamber comprising an inner perforated wall and an outer imperforated wall, a closely coiled fibrous cord located in and filling said chamber, said chamber communicating with the interior of the cylinder to provide a drain back intothe cylinder, and an outlet leading from said outer wall to the storage tank. V

7. The combination with an air compressor including a piston cylinder, a crank case in communication with the interior of the cylinder through which air to be compressed in the cylinder enters the latter, and lubricating means including the lubricant within said crank case for lubricating parts of the compressor, of a device arranged above and in alinement with said cylinder for separating or removing from the air any lubricant in the air after the'latter leaves the compressor, said device communicating with the interior of the cylinder to allow unvaporized lubricant to drain therefrom into the top of the cylinder.

8. The combination with an air compressor including a piston cylinder, a crank case in communication with the interior of the cylinder through which air to be compressed in the cylinder enters the latter, and lubricating means including the lubricant within said crank case for lubricating parts of the compressor, of a device for separating or removing from the air any lubricant in the air after the latter leaves the compressor, said device including a chamber detachably secured to the top of said cylinder in axial alinement therewith, and closely packed fibrous material tightly filling said chamber, said chamber communicating with the interiorof the cylinder to allow unvaporized lubricant to drain therefrom into the top of the cylinder, said chamber having an air outlet.

GREGORY J. SPOHRER. 

